The present invention relates to an image forming apparatus such as a copying machine, a printer and a facsimile machine.
There has been known an image forming apparatus capable of so called enlarged divisional printing wherein in case of forming an image on a sheet by enlarging image data of a document, if the enlarged image data of the document becomes larger than the size of the sheet, the image data is divided and formed on a plurality of the sheets (for example Patent Document 1). Thereafter a plurality of the sheets on which divided images are formed are jointed by a user to obtain an enlarged image.    [Patent Document 1] Tokkai 2004-325492
In case an enlarged image is formed by jointing a plurality of the sheets, it is required for adjacent sheets that on one sheet, an overlap width has to be provided at a side to be jointed with an adjacent sheet, and on the other sheet, an image has to be formed to the edge of the sheet. If the image is formed by ordinary page margin printing where page margins are always formed, the page margins are formed at four sides of the sheet, thus the unnecessary page margins have to be cut away before jointing.
In such case, full breed printing which forms the image to the very edge of the sheet is required. However, full breed print is usually configured to be selected by a user for the reasons below. Thus if the user misses to select full breed printing the unnecessary page margins are created at four sides which have to be cut away.
In full breed printing, since the image forming involves toner running off the edges of the sheets, the transfer member tainted by the toner running off has to be cleaned. Thus productivity is deteriorated compared to page margin printing. Therefore, for full breed printing, let the user select the full bread printing so as to confirm the user's will which accepts full bread printing though the productivity is deteriorated.